1. Field of the Invention
The present invention relates to an image displaying apparatus and an image displaying method that controls a quantity of light to propagate through a light path when there is a fault in the light path when displaying an image.
2. Description of the Related Art
A projector-type image displaying apparatus is known in the art that modulates light output from a light source, and enlarges and projects the modulated light onto a screen. Specifically, in the projector-type image displaying apparatus, the light output from the light source is collected at a lens, and then illumination intensity across a cross section of the light flux is made uniform. Subsequently, the light with uniform illumination intensity is modulated, and enlarged and projected on the screen to display the image. A spatial light modulator is used to modulate the light.
A micromirror device, such as a digital micro-mirror device (DMD) (Registered Trademark), is used as a spatial light modulator (light modulating element). The light emitted from the light source is filtered through a color wheel and then passed to the spatial light modulator. The light modulator reflects the light selectively, according to video signals; therefore, only valid lights are projected onto the screen through projecting lens. A related technology has been disclosed, for example, in Japanese Patent Application Laid-Open No. H9-163391.
To accommodate an optical system (light path) from the light source to the light modulator in a chassis of a limited depth, it is sometimes necessary to separate the light source and light modulator. If the light source and light modulator are separates, then it becomes necessary to create a light path from the light source to the light modulator with the help of mirrors, prisms, optical fibers, etc. However, in such an arrangement, a fault may occur due to degradation of a reflecting surface of the mirror or the optical fiber. The light modulator can not receive appropriate quantity of light if there is a fault. This may result in a disturbed image displayed on the screen.